Improved operating-chair



-NTTED STATES PATENT Duuren.

JAMES BEALL MORRISON, OF ST. LOUIS, .MISSOURI IMPROVEDOPER/\TlNG-=CHAIR.

Specification forming part of Letters Patent No. 82,542, dated September29, 1863; patented in England, December 7, 1867'.

To all whom it may concern:

Be it known that I, J AMES BEALL MonnisON, of St. Louis, in the State ofMissouri, have invented certain new and useful Improvements in theConstruction of Operating-Chairs, more especially designed for dentists,part of such improvements being applicable to other purposes; and-I dohereby declare that the following is a full and exact descriptionthereof, reference being had to the accompanying drawings and theletters of reference marked thereon.

The nature of my invention consists in a novel mode of raising andlowering the body of a chair, and in the novel means employed foradjusting' and'securing the same at any required angle; further, inconstructing an operating-chair with arms adjustable in reference to thescat of the same, and in the arrangementfor adjusting and securing theback; and, further, in the manner of adjusting the head-rest of anoperating-chair, and in so constructing and combining the various partsin an operating-chair as to enable it to be adjusted to adapt it toadults or children.

In the accompanying drawings, Figure I, Sheet l, represents asideelevation of a dentists operatingchair, constructed according to myinvention. Fig. II is a vertical section of thesame, and Fig. III is aback view of said chair. Fig. IV, Sheet II, is a horizontal section onthe line fr, Fig. III. Fig. V shows the movable back of the chair-bodydetached. Fig. VI is a section at line y y, Fig. III; and Fig. VII showsanother detached portion of the said chair.

Similar letters represent similar parts in all the figures. V

The stand or foot A is formed of cast-iron, or other suitable material,and is lmade of the proper size and weight to give a iirm and solidsupport to the body B of the chair while being used in whatever positionthe same may be adjusted. This body of the chair, B, is connected withthe foot or stand A by means of a universal joint, C, which consists ofa hollow hemispherical piece, a, a cup or socket, b, and a convex piece,d. The part b of the said universal joint is attached to the stand orfoot A, while the hollow hemispherical piece a of the said joint isattached to slides f, which extend upward and downward from the saidjoint at the back of the chair.

To the convex piece d, a bolt g, is attached, which, when tightened,connects the socket b with the hemispherical piece et, and thus locksthe two parts of the joint securely together. The bolt g is jointed tothe foot-lever h, which is formed with the cam or projection 3. Y'Vhen.this lever h is depressed, as shown in Fig, II, this cam 3 pressesagainst the stand A, and thereby tightens the bolt g. By slackening thesaid bolt, the hemispherical piece a will be allowed to move freely inthe socket b, and will thus allow the body B of the chair to be adjustedin any desired position. The bolt g can then be tightened, the cup b andconvex piece d being thereby made to bind closely upon the hemisphericalpiece a, and thus hold the parts of the joint securely and immovablytogether. The aperture in the stand or foot A, through which the boltgpasses, is lunch larger than the said bolt, to allow the requiredadjustmentof the hemispherical piece a within its cup. v

To the body B of the chair pieces u are securely fastened, (shown inlFie'. VIIseparate,) capable of moving in suitable grooves or guides iuthe slides f, and allow the body of the chair B to be moved upward ordownward. An` elevating screw or screws may be arranged between theseslides f,- but I prefer that the chair should be provided with pinionsm, geared into toothed racks p, attached to the slides j". A

The pinions m are iixed on an axle, 7.', arranged in suitable bearingsin the frames or, and are provided with a handle, l, arranged at theside of theehair. By turning the handle, the entire body B can beconveniently raised or lowered, as desired. The shaft or axle l.: alsocarries a ratchet-wheel, q, which is arranged, in connection with apawl, l1' in such a manner as to prevent the lowering of the chair byits own weight when the handle Z is released.

The pawl Ai is attached to a lever pivoted to the side ofthe chair, andarranged with a suitable spring to keep the pawl in gear with theratchet-wheel until it is desired to raise or lower the chair, when theratchet-wheel is` released by pulling back the lever, which ex:

tends upward for convenience of manipulation.

rIhe back R of the chair is constructed to slide independently up anddown at the rear of the seat, and may be jointed to the arms D; but Iprefer to connect the arms to the sides of the body B of the chair.

Fig. VI, which is an enlarged section on the line y y, Fig. III,illustrates the arrangement of the slides j' and sliding back It.Oruciform pieces or frames a (a side elevation of which is shown in Fig.VII) are attached to the body B of the chair by suitable lugs, and aretted to move up and down in the slides f, and also form guides for thelegs R of the adjustable back R. These pieces a also carry the bearingsfor the shafts L and 1'. The latter is provided with a cam, s, at eachend, to secure the back R in any desired position. The shaft r isoperated by the handle t, and the cams s act against the back of thelegs R of the movable back It.

I prefer to adopt the method of construction illustrated in Figs. I, II,and III, in which the arms D are arranged to move up and downindependently of the back R in the following manner: Each arm is formedwith a tlat piece, r, extending"downward, which piece fits betweenguide-pieces 10 on the side ot' the seat or body B ot' the chair. Apinching-serew, z, passes through the piece fu and through a suitableslot, which screw serves to lock the arms in any position into whichthey may be adjusted.-

Instead ot' a screw, an eccentric or other suitable pinching device maybe fitted in any convenient position of the guides w, which are made ofsutiicient length and are so arranged that the arms are supported tirmlytherein, but will slide freely up and down when released i'rom thepinching-screw or other device.

The head-rest F for my improved chair is supported upon a universaljoint, E, of similar construction to that employed below the seat orbody of the chair. The cup or socket b ot the said joint is arrangedupon the top l of a flat bar, 2, extending from the back It of thechair. The upper part of this bar is formed with a long aperture orslot, through which the pinching-screw g of the joint ex tends, the nutbeing placed below the bar 2. rlhe headrest F is attached to thehemispherical piece a of the joint.

rlhe said rest is preferably formed with two cushions, 12 and13, tosupport the head. One ot' these cushions, 13, is just over the joint E,while the other, 12, projects beyond the same.

By turning the rest around upon the joint, either cushion may be used,each one being especially adapted to support the head d urin g certa-inparticular operations. If preferred, however, a rest ot' ordinaryconstruction may be employed.

When the screw g' is slackened, the rest F can be adjusted into anyrequired angular position, can be turned round upon the screw g', andcan also be moved on the slotted bar 2 nearer to or farther from theback R ofthe chair. The screw g is then tightened, locking the two partsa and b of the joint E together, and also securing the rest upon the bar2 at one operation.

The part 5 of the bar 2, which is secured to the back R ot' the chair,is formed with a long aperture or slot, and the back of the chair has atransverse slot, 6. A screw, S, passes through the two slots to hold thebar 2, which, by means of the said slots, can be elevated and depressed,or moved laterally, and adjusted to any desired position. The pin 7serves to steady the lower end ofthe said bar.

What I claim as my invention, and desire to secure by Letters Patent,is-

1. The combination ot' a universal joint, O, with slides f, extendingupward and downward from said joint, and provided with suitable grooves,in which suitable pieces n, fast to the bo`dy of an operating-chair, aremade to slide, constructed substantially inthe manner and for thepurpose described.

2. The application of a universal joint, E, constructed in the mannerhereinbefore described, to the head-rest of an operating-chair, incombination with the slotted bar 2, constructed and arranged andoperating together in the manner substantially as specified.

3. A head-rest, F, made with two cushions or head-supporters, 12 and 13,in combination with a universal joint, E, and slotted bar 2, arrangedand operating in the manner substantially as set fort-h and specified.

4. The arrangement of the cruciformed frames n, attached to the body ofthe chair I3, the slides f, attached to the universal joint O, incombination with the racks 1J and piliions m, for elevating anddepressing the body of the chair, when constructed and combined in themanner and for the purpose substantially as described.

5. Arms D, provided with suitable pieces r, extending downward, andfitting between guide-pieces a', fast on the sides ot' the chair, andprovided with a pincl1ingscrew or other device to tix the arms in anydesired position, substantially in the manner and for the pur` posedescribed.

JAMES BEALL MORRISON.

Witnesses:

HENRY E. Rennen, WVM.

